Refrigerating apparatus



Nov. 29, 1966 J. A. BRIGHT REFRIGERATING APPARATUS Filed Sept. 2, 1965 INVENTOR. James A. Brig/7f His Afforney United States Patent 3,287,924 REFRIGERATING APPARATUS James A. Bright, Miamisburg, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Sept. 2, 1965, Ser. No. 484,531 2 Claims. (Cl. 62-5) This invention pertains to refrigerating apparatus and more particularly to a two evaporator two-temperature refrigerating system in which the temperature difference is provided by a vortex tube.

Many different arrangements have been conceived for providing two different temperatures in a refrigerating system. Some are ineflicient and some are eflicient but expensive and complicated. Many require additional valves in the system which are possible sources of trouble.

It is an object of this invention to provide a simple eflicient two-temperature refrigerating system which is not dependent on valves for obtaining the temperature difference.

It is another object of this invention to provide a simple efficient low-temperature refrigerating system with a simple effective temperature adjustment.

These and other objects are obtained in the form shown in the drawings in which a restrictor tube feeds the liquid refrigerant tangentially to a helical groove in the inner cylindrical wall of a vortex tube. The refrigerant issues from the capillary tube at a high velocity into the vortex tube with the vapor in the central portion of the vortex tube being conducted to the food compartment evaporator while the liquid in the outer portions of the vortex tube is conducted to the freezer compartment evaporator. The vapor or evaporated refrigerant from the two evaporators is returned to the compressor inlet. The temperature of the food compartment evaporator is adjusted through the provision of a simple adjusting valve in the supply conduit of the freezer compartment evaporator. The food compartment evaporator is preferably adjusted to operate at above freezing temperatures, but if desired it can operate at below freezing temperatures.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a diagrammatical view of a refrigerating control system embodying 2-evaporator, Z-temperature refrigerating system incorporating one form of my invention;

FIGURE 2 is an enlarged, longitudinal sectional view of the vortex tube illustrated in FIGURE 1, taken along the line 22 of FIGURE 3; and

FIGURE 3 is a transverse sectional view of the vortex tube taken along lines 3-3 of FIGURE 2.

Referring now more particularly to FIGURE 1, there is shown a refrigerant compressor 20 normally driven by an electric motor 22 which draws evaporated refrigerant from the high and low temperature evaporators 28 and 32 and compresses the evaporated refrigerant and pumps it into a condenser 24 where the condensed refrigerant is liquified and supplied through a restrictor tube 26. The refrigerating system includes a food compartment evaporator 28 located in the above freezing food com partment 30 and a lower temperature freezing compartment evaporator 32 for maintaining below water freezing temperatures in the freezing compartment 34. The suction line 36 connects the outlet of both the evaporators 28 and 32 to the compressor inlet.

3,287,924 Patented Nov. 29, 1966 According to my invention, to keep the freezing compartment evaporator 32 at temperatures substantially below the temperature of the food compartment 30 the capillary restrictor tube 26 feeds tangentially into a vortex tube 38. As illustrated in FIGURES 2 and 3, this capillary tube 26 is arranged to provide a tangential inlet 40 through the wall 46 to the interior of the tube 38 and has an outlet 42 feeding tangentially a helical groove 44 in the cylindrical wall 46 of the vortex tube 38. The helical groove 44 advances to the right in FIGURE 2. The liquid refrigerant is fed through the capillary tube 26 at a relatively high pressure and toward the end of the tube, begins to vaporize as the pressure is reduced. This increases the velocity so that the liquid with a small amount of vapor is discharged from the outlet tube 42 at a relatively high velocity. This liquid refrigerant along with some vapor then flows rapidly in a helical path provided by the groove 44.

The relatively high velocity of the liquid and small amounts of vapor discharging into the helical groove of the vortex tube causes the higher density liquid to be centrifugally forced to accumulate in the helical groove and therefore is directed to the tube 58, while the less dense vapor accumulates toward the center of the vortex tube and flows out tube 50. This tube 50 extends to the left through the end wall 52 of the tube 38 and connects to the inlet of the food compartment evaporator 28. The opposite end of the tube 50 is closed by the internal flow directing member 54. This internal flow directing member 54 is located adjacent the necked down portion 56 of the tube 38. The member 54 guides the refrigerant adjacent the outer wall 46 into the tube 58 of reduced size which connects to the inlet of the freezing evaporator 32.

Since the liquid refrigerant can pick up more heat, tube 58 of reduced size connects with the inlet of the lower temperature freezer compartment evaporator. The centrally located tube 50 connects with the inlet of the higher temperature food compartment evaporator in which vapor refrigerant is fed, since the vapor refrigerant has less capacity to pick up heat.

Through this arrangement the temperature of the food compartment evaporator 28 can be lowered by closing the throttling valve 60 which throttles the flow of refrigerant into the inlet of the freezer evaporator 32 and causes the liquid refrigerant to back up in the vortex tube, thus causing some of the liquid refrigerant in the vortex tube to leave through the centrally located tube 50 which connects with the inlet to the food compartment evaporator, therefore increasing the capacity of the refrigerant entering the food compartment evaporator 32 to pick up more heat.

In this arrangement, some of the liquid refrigerant discharged from the outlet 42 of the capillary 26 into the vortex tube 44 evaporates to pre-cool the remaining liquid to a low temperature. This evaporated refrigerant then flows out through the tube 50 and the evaporator 28 and has capability for cooling the food compartment 30. The remaining liquid refrigerant which is thus pre-cooled then fiows through the tube 28 and the evaporator 32 to cool the freezing compartment 34. This provides an efficient system for cooling both the food compartment and the freezer compartment since the vapor resulting from the pre-cooling of the refrigerant liquid is capable only of absorbing heat at the relatively high temperature prevailing in the food compartment. This leaves the remaining pre-cooled liquid having an inherent capability of absorbing heat at lower temperatures for passage through the freezing evaporator 32 for cooling the freezing compartment 34 to low temperatures.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. Refrigerating apparatus including first and second refrigerant evaporating means having inlet and outlet means, refrigerant compressing and condensing means having inlet means connected to the outlet means of said first and second evaporating means, vortex means having a central outlet means connected to the inlet means of said first evaporating means and an outer outlet means connected to the inlet means of said second evaporating means, means for changing the pressure energy of the refrigerant to velocity energy comprising a restrictor having its inlet connected to the outlet means of said compressing and condensing means and having its outlet discharging substantially tangentially into the inner surface of said vortex means.

2. Refrigerating apparatus as defined in claim 1 having means for controlling the flow of refrigerant from said outer outlet means to said second evaporating means to lower the temperature of said first evaporating means.

References Cited by the Examiner UNITED STATES PATENTS 2,920 457 1/1960 Bartlett 62 5 WILLIAM J. WYE, Primary Examiner. 

1. REFRIGERATING APPARATUS INCLUDING FIRST AND SECOND REFRIGERANT EVAPORATING MEANS HAVING INLET AND OUTLET MEANS, REFRIGERANT COMPRESSING AND CONDENSING MEANS HAVING INLET MEANS CONNECTED TO THE OUTLET MEANS OF SAID FIRST AND SECOND EVAPORATING MEANS, VORTEX MEANS HAVING A CENTRAL OUTLET MEANS CONNECTED TO THE INLET MEANS OF SAID FIRST EVAPORATING MEANS AND AN OUTER OUTLET MEANS CONNECTED TO THE INLET MEANS OF SAID SECOND EVAPORATING MEANS, MEANS FOR CHANGING THE PRESSURE ENEREGY OF THE REFRIGERANT TO VELOCITY ENERGY COMPRISING A RESTRICTOR HAVING ITS INLET CONNECTED TO THE OUTLET MEANS OF SAID COMPRESSING AND CONDENSING MEANS AND HAVING ITS OUTLET DISCHARGING SUBSTANTIALLY TANGENTIALLY INTO THE INNER SURFACE OF SAID VORTEX MEANS. 